HUT (Hutterite)

Inheritance: autosomal recessive
Genes:unknown

homozygosity at c16p13.3

Microcephaly, mental retardation, and distinctive facies, with cardiac and genitourinary malformations

Developmental delay
Facial dysmorphism
Genitouringary anomalies
Cardiac malformations
High forehead
Long nose
VSD
Cognitive defects

Beaulieu-Boycott-Innes Syndrom; BBIS

Clinical Characteristics

General description (for patients):  

This syndrome has growth and developmental delays and is further characterized by a typical facial appearance, abnormal kidneys, and openings in the heart. No gestational problems have been described but birth weight and head circumference are low (in the range of the 5th centile), and subsequent growth is slow with post-pubertal stature in the same range. Physical and muscle movements are in the normal range but language is delayed and learning problems are evident in kindergarten and most eventually are able to function only at the 4th grade level even as adults. The various anatomical abnormalities generally do not require medical or surgical treatment and the major health problems are related to the mental handicaps.

Medical description:   

The features of this syndrome as described in a single report are based on a description of 4 individuals. The face is described as characteristic with a high forehead, high anterior hairline, deep-set eyes with upward slanted lid fissures, a long nose and prominent vermilion of the lips. Birth weight and occipitofrontal circumference is usually in the 5th centile range and subsequent development leads to eventual stature in the same range. Gross and fine motor skills are usually normal but language and cognitive skills are impaired throughout life. Impaired learning skills are evident by kindergarten if not sooner and adults are unlikely to advance beyond the 4th grade level of cognitive reasoning.
 
Anatomic anomalies include malformations of the genitourinary system (absent and duplicated kidneys), and cardiac defects such as ventricular septal defects and persistent ductus arteriosis. Dental caries, micrognathia, recurrent urinary tract infections and premature ovarian failure (all individuals have been female) are also features. Brain CT scan and MRI in one adult were normal.

Genetics:

This is a presumed autosomal recessive disorder based on its familial occurrence (two sibs in each of two families) descendent from a common ancestral couple. All reported cases have been female but this is likely a chance occurrence since there is no history of fetal wastage in either family and there is no evidence of X chromosomal defects (results of karyotyping were normal). In addition, although no molecular gene defect has yet been identified, a common region of homozygosity on chromosome 16 (16p13.3) was shared among all four patients and not present in unaffected sibs. 

Treatment:

The renal and cardiac anomalies have not required surgical treatment. There is no known treatment for the cognitive and developmental delays.

Prognosis:

Unknown. No childhood deaths have been reported and at least two individuals have lived at least into the third decade. 

Ancillary treatments and support:

Supportive. Urinary tract, pulmonary, and dental infections require prompt treatment.

Specialists and pecialty centers:

neurologist, learning specialists, cardiologist, dentist 

References:

Boycott, K. M., Beaulieu, C., Puffenberger, E. G., McLeod, D. R., Parboosingh, J. S., and Innes, A. M.: A novel autosomal recessive malformation syndrome associated with developmental delay and distinctive facies maps to 16ptel in the Hutterite population. Am. J. Med. Genet. (A) 152A 1349-1356, 2010. PubMed ID: 20503307